The Beginning:[]
House Brax was established during the Andal invasion through the marriage of First Men and Andal nobles.
The Blackwater Rebellion[]
House Brax raised their banners in favor of the Usurper, Aemon Targaryen. They fought in the Battle of the Rock where the Daryn Brax, Lord of Hornvale was slain and his body never found. The following year House Brax kneeled to Daeron Targaryen and became the bannermen of House Lannister of the Westerlands.